1. Field of Invention
This invention relates generally to toner cartridges for laser printers and photocopying machines, and in particular to removable lid apparatus usable during the toner recharging process to cover the access opening of the blade housing segment of the cartridge so that the cartridge becomes reusable.
2. Description of the Background
Toner cartridges used in electro photographic copiers are structured quite differently from each other, depending on the particular machine in which the cartridge is intended for use. Further, many toner cartridges are intended for a single use, and the used cartridge is to be discarded after the toner is depleted. Commonly, to resolve toner leakage problems, toner cartridges include a toner hopper, a seal assembly, a mounting member, a roller assembly, a drum assembly and a corona assembly. Unfortunately, this arrangement is expensive, and many components of the cartridge are still usable after the toner has been expended. Consequently, many portions of the toner cartridge are configured so that they may be reused. However, if other portions of the used cartridge may be reused on a regular basis, more structural resources can be preserved and operating costs can be lowered.
U.S. Pat. No. 4,862,210 describes such a replaceable seal assembly for modifying and recharging a used Canon toner cartridge of the type having an upper toner reservoir and a lower roller housing joined along its common edges with the toner reservoir housing and separated therefrom by an original toner reservoir seal, which is removed when the cartridge is placed into use. Originally, the entire developer cartridge was intended to be thrown away, but the modification provides a replaceable seal assembly wherein an elongated, rigid seal member can be inserted longitudinally into a peripheral recess formed between the toner reservoir and the lower roller housing, thus allowing the cartridge to be refilled and reused on a regular basis. Pat. No. 5,223,068 describes method and apparatus wherein a table saw is used to separate the toner hopper from a mounting member, and a hand held plane is utilized to prepare facing gasket surfaces on the toner hopper and the mounting member, wherein a new seal assembly, comprising a gasket and a folded seal member, is glued between the hopper and the mounting member to seal the discharge opening. A portion of the folded seal member forms a tab, which when pulled, allows the seal member to be removed from the gasket, uncovering the discharge opening and placing the cartridge in use. U.S. Pat. No. 5,110,646 discloses a reconditioned toner cartridge, which when deployed for use, the user pulls a perforated center strip from under the magnetic roller housing, thus exposing the toner and energizing the cartridge for use. U.S. Pat. No. 4,816,877 discloses a refillable toner cartridge wherein the toner hopper is provided with a refill hole which is covered by a washer over which a seal member having an adhesive layer is attached; and wherein the discharge holes of the waste toner hopper chamber are covered by a seal member, which has an adhesive layer and which may be made of a permeable material to permit air to pass through, and not toner particles so that the cartridge can be forwarded by air transport. U.S. Pat. No. 4,870,463 discloses another toner cartridge wherein the seal element extension is pulled to strip the sealing portion of the sealing member from the lower surface of the toner box, thus opening the lower surface of the toner box.
However, the Canon toner cartridge assembly described in U.S. Pat. No. 5,134,960 is different. The Canon toner cartridge assembly described therein includes an upper, blade housing segment, which contains a cleaning blade that wipes against the photosensitive member to remove residual developer remaining on the photosensitive member after image transfer, which is retained within the cavity of the blade housing. Originally, the cavity of the blade housing segment is provided with an access opening, over which a rigid plastic cover piece is glued, and which remains in place while the cartridge is placed in service. However, in order to remanufacture or refurbish the toner cartridge, the cleaning blade may need servicing, and the cavity of the blade housing may need cleaning to remove the residual developer. Consequently, in order to gain access to the cleaning blade and the cavity of the blade housing, the plastic cover piece must be broken loose from its engagement with the blade housing. Ordinarily, the cover piece may break, and when removed, the peripheral sealing area depression which surrounds the access opening is left in a toughened state. In the past, some users have tried to recover the access opening with a piece of tape, but this has not been found to be entirely satisfactory because of leakage. Others obtain a new blade housing and discard the old blade housing, which is expensive and wasteful. Therefore, there is a need for a seal arrangement which allows the original blade housing to be reused on a regular basis.